1. Field of the Invention
This invention generally relates to a bicycle pedal assembly. More specifically, the present invention relates clipless or step-in bicycle pedal assembly, which has cleats that are releasably coupled to a pair of bicycle pedals.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle as well as the frame of the bicycle. One component that has been extensively redesigned is the bicycle pedal.
In recent years, bicycle pedals have been designed for specific purposes such as for pleasure, off road biking, road racing, etc. One particular type of bicycle pedal, which is gaining more popularity, is the step-in or clipless pedal, which releasably engages a cleat secured to the sole of a cyclist's shoe. The clipless pedal has a pedal spindle that can be mounted on the crank of a bicycle, a pedal body that is rotatably supported on this pedal spindle, and a cleat engagement mechanism. In an off road bicycle pedal a cleat engagement mechanism is formed on both sides of the pedal body for engaging a cleat. A road-racing pedal, on the other hand, typically only has a cleat engagement mechanism on one side of the pedal body. In either case, in these types of bicycle pedals, the rider steps onto the pedal and the cleat engagement mechanism automatically grips on to the cleat secured to the bottom of the cyclist's shoe.
With this type of step-in or clipless pedal, the shoe and the pedal are in a state of constant engagement when the cleat is engaged in the cleat clamping members, so the pedaling force can be transmitted efficiently to the pedals. As a result, step-in or clipless pedals are widely employed on racing bicycles used in road racing and mountain bike racing.
When attaching the cyclist's shoe to the step-in or clipless pedal via the cleat, the cyclist moves the shoe obliquely downwardly and forwardly relative to the pedal body such that the front end of the cleat engages a front hook or clamping member of the pedal body. Once the front end of the cleat is engaged with the front hook of the pedal body, the cyclist places the rear end of the cleat in contact with a guide portion of the rear hook or clamping member of the pedal body. In this position, the cyclist presses the shoe downwardly against the pedal to cause the rear hook or clamping member to initially pivot rearwardly against the force of a spring to move the rear hook or clamping member to a cleat releasing position. The rear end of the cleat then enters a position opposite a back face of the rear hook or clamping member. Then, the rear hook or clamping member returns under the force of a biasing member or spring so that the rear hook or clamping member engages the rear end of the cleat. This engagement fixes the cyclist's shoe to the pedal via the cleat.
When releasing the shoe from the pedal, the cyclist will typically turn the shoe about an axis perpendicular or approximately perpendicular to the tread of the pedal, using the front end of the cleat as a pivoting point. As a result of this pivoting action, the rear nook or clamping member is pivoted rearwardly against the force of the spring to a cleat releasing position to release the shoe. It is important that the cleat does not inadvertently release the pedal during normal pedaling. Some of these prior step-in or clipless pedals can inadvertently release the cleat during normal pedaling if the spring force on the rear clamping member is set too low. However, if the spring force on the rear clamping member is set too high, the cleat may not release from the pedal properly. This could result in the rider's shoe not properly releasing from the pedal at the desired application of force because the rider's shoe either releases too easily from the pedal or does not release at the proper time. Thus, some of these step-in or clipless pedals and the cleats for these pedals are designed with adjustment mechanisms to change the release force required for the rider to disengage the cleat from the pedal. However, these adjustment mechanisms increase the overall cost of the pedals. In particular, these adjustment mechanisms can be complicated and expensive to manufacture and assemble.
In view of the above, there exists a need for an improved bicycle pedal assembly that takes into account at least some of the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.